Shut the Box: roll the dice, flip down the tiles

Shut the Box, free online

Shut the Box is a dice game played with a wooden box and a row of numbered tiles. You roll two dice, then flip down tiles that add up to the number you rolled. The aim is to shut every tile. Most turns end before that, with a few tiles still standing, and those tiles are your score. A low score is good, and zero is the dream.

This version follows the most common rules: nine tiles, two dice, and the option to roll a single die once the 7, 8 and 9 are down. You can also switch to the Full House box with tiles 1 to 12 for a much tougher game. Play alone to beat your best score, play five rounds for a total, take on the computer at Easy or Hard, or pass the phone to a friend for a two player match.

How to play here

Press Roll. The dice tumble across the felt and the total appears next to them. Tap the tiles you want to shut. The running sum shows under the total, and tiles that can no longer fit your roll fade out, so you never pick a combination that cannot work. When your tiles add up to the roll, press Shut and they flip down with a clack.

When the 7, 8 and 9 are shut, a second button lets you roll one die instead of two. If no open tiles add up to your roll, the turn ends on its own and the open tiles are counted.

The buttons under the box help you along. Hint shows the statistically best move for your roll and your chance to shut the box after it. Undo takes back the last tile you picked, and Restart deals a fresh game. The pause button at the top keeps your place.

The numbers behind the box

Shut the Box looks simple, but it is a neat probability puzzle. We solved it completely. For every possible set of open tiles, we worked out the best chance of finishing with every tile shut, taking every roll and every possible choice into account. The Hint and the Hard computer both use that table.

A few results stood out:

1. Perfect play shuts the 1 to 9 box 9.76% of the time. The table and a simulation of 200,000 turns agree on this.
2. The highest tile is usually right. “Shut the biggest tile you can” matches perfect play in about 88% of the choices that matter. The exceptions come late in a turn, when two middle tiles keep you more options than one big tile plus the small ones.
3. The one die choice matters more than most people think. One die is better only when the open tiles add up to 6 or less. Players who always take the single die when allowed shut the box far less often.
4. Full House is brutal. With tiles up to 12, even perfect play shuts the box only about once in 210 tries.

So skill counts, but the dice decide most turns. That is part of the charm: a beginner can beat an expert on any given round, and the expert still wins more often over a long evening.

A short history

Nobody knows for sure where Shut the Box began. Many stories link it to sailors in northern France centuries ago, but there is no firm record of its origin. What is clear is that it has been a familiar pub game in Britain for a long time, often played for small stakes. It also travels under other names, including Canoga and Batten Down the Hatches.

The wooden box with flip-down tiles is the classic set, and plenty of homes still have one in a cupboard. Rules vary from table to table. Some players allow one die only when the open tiles add up to 6 or less, some read the open tiles as one number (1 and 4 left counts as 14), and some play tiles up to 12. The rules here are the widely played ones, and the one die rule is shown on the box as you play.

Why play Shut the Box?

A round takes a minute or two, so it suits a short break. It is also quiet practice in quick addition: every roll asks you to find the ways to make a number from the tiles you have left. Children pick it up fast, and adults get hooked trying to bring their best score down to zero.

If you like dice and counting, try Mancala for a game of sowing and capturing with no luck at all, or test your sums against the clock in Mental Math.

How to play Shut the Box

1. The box holds nine tiles numbered 1 to 9 (1 to 12 in the Full House version). Every tile starts open.
2. Roll two dice. Shut any open tiles that add up to the total. A roll of 8 can shut the 8, or 5 and 3, or 1, 3 and 4.
3. Once the 7, 8 and 9 are all shut (7 and up on the Full House box), you may roll one die instead of two. It is your choice.
4. Keep rolling until no open tiles add up to your roll. Your turn ends, and your score is the sum of the tiles still open. Lower is better.
5. Shut every tile and you score 0. That is shutting the box.
6. Against the computer or a friend, each player takes one turn per round with a fresh box. The lower score takes the round, and the first to win three rounds wins the match.

Shut the Box tips

Shut the big tiles first

The 7, 8 and 9 are the hardest tiles to get rid of late in a turn. With only those three left, you finish just 1.5% of the time. On a roll of 9 at the start, shutting the 9 leaves a 14.5% chance to shut the box; 4 and 5 leaves 6.4%.

Two tiles beat three

Small tiles are your spare change. A 7 played as 3 and 4 keeps a 4.7% chance to shut the box, while 1, 2 and 4 keeps only 1.9%. Use as few tiles as you can and save the 1, 2 and 3 for the end.

Big first rolls

On the opening roll, a 10 is best played as 9 and 1, an 11 as 9 and 2, and a 12 as 9 and 3. Clearing the 9 early is worth spending one small tile.

One die only at 6 or less

Roll one die only when the open tiles add up to 6 or less. With 3 and 4 open, for example, two dice still give you better odds. For a player who always shuts the highest tile, taking one die every time it is allowed cuts the chance to shut the box from 9.5% to 5.6%.

Don't follow "highest tile" blindly

Late in a turn, keeping small tiles can matter more. With 1, 2, 3, 5, 6, 7 and 8 open and a roll of 12, playing 5 and 7 gives a 14.1% chance to finish, about twice as good as 1, 3 and 8.

Frequently asked questions